WATER & WASTEWATER
uMshwathi Regional Bulk Water Supply Scheme Phase 2 Umgeni Water appointed Hatch to design and manage the construction of the uMshwathi Regional Bulk Water Supply Scheme Phase 2. This comprised a 15 km, 700 mm diameter steel pipeline between War tburg and Dalton, two booster pump stations, and a 10 Mℓ reser voir.
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he project was located in the uMshwathi Local Municipality north-east of Pietermaritzburg in KwaZulu-Natal. The municipality falls within the uMgungundlovu District Municipality, which is responsible for the supply of water to consumers within this region.
Booster pump stations The 58 Mℓ/day Mpolweni pump station was designed and constructed at km 19.3 on the 27.7 km long 850 mm diameter pipeline built in Phase 1. The pipeline had been constructed under a separate contract and was practically complete at the time of commencement of the construction of the pump station. The
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IMIESA July 2021
Mpolweni pump station consists of three pumpsets in parallel with a combined installed capacity of 900 kW, with future upgrading planned to 2.25 MW. The pumpsets installed for the initial two duty points were designed to run at 860 rpm and 1 065 rpm, respectively, using variable-speed drive (VSD) technology – allowing for flows rates from 1 620 m3/h to 2 180 m3/h. The pump station has been configured to operate with a single duty pump when required. Consisting of two pumpsets with a combined installed capacity of 1.5 MW, the 41 Mℓ/day Dingle pump station operates with one pump on duty and one pump on standby. These pumpsets are designed to run at 1 350 rpm and 1 450 rpm, respectively, using
The Dalton Reservoir site
PROJECT TEAM Client: Umgeni Water Principal design consultant and construction manager: Hatch Electrical consultant: Adamastor Consulting Cathodic protection consultant: Paradigm Projects Environmental consultant: Afzelia Health and safety agent: ORM Principal contractor: Icon Construction Mechanical and electrical subcontractor: Oro Projects / Electron
VSD technology. This allows for flow rates from 980 m3/h to 1 320 m3/h. A future third pump was allowed for in the design, where two pumps will operate as duty with a third pump on standby. The Dingle pump station was constructed about two thirds down the Phase 2 pipeline route to boost pressure in order to supply the Dalton Reservoir. Using the VSDs, these pump stations can meet projected system demands to 2035 using the same mechanical and civil infrastructure (including pumps). In order to achieve the ultimate 40-year demands, only the motors and the electrical switchgear would need to be upgraded, which will be necessary due to their design life in any event.
